samples/ffi/sample_ffi_functions.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:ffi';

import 'package:ffi/ffi.dart';

import 'dylib_utils.dart';

typedef NativeUnaryOp = Int32 Function(Int32);
typedef NativeBinaryOp = Int32 Function(Int32, Int32);
typedef UnaryOp = int Function(int);
typedef BinaryOp = int Function(int, int);
typedef GenericBinaryOp<T> = int Function(int, T);
typedef NativeQuadOpSigned = Int64 Function(Int8, Int16, Int32, Int64);
typedef NativeQuadOpUnsigned = Uint64 Function(Uint8, Uint16, Uint32, Uint64);
typedef NativeFunc4 = IntPtr Function(IntPtr);
typedef NativeDoubleUnaryOp = Double Function(Double);
typedef NativeFloatUnaryOp = Float Function(Float);
typedef NativeDecenaryOp =
    IntPtr Function(
      IntPtr,
      IntPtr,
      IntPtr,
      IntPtr,
      IntPtr,
      IntPtr,
      IntPtr,
      IntPtr,
      IntPtr,
      IntPtr,
    );
typedef NativeDecenaryOp2 =
    Int16 Function(
      Int8,
      Int16,
      Int8,
      Int16,
      Int8,
      Int16,
      Int8,
      Int16,
      Int8,
      Int16,
    );
typedef NativeDoubleDecenaryOp =
    Double Function(
      Double,
      Double,
      Double,
      Double,
      Double,
      Double,
      Double,
      Double,
      Double,
      Double,
    );
typedef NativeVigesimalOp =
    Double Function(
      IntPtr,
      Float,
      IntPtr,
      Double,
      IntPtr,
      Float,
      IntPtr,
      Double,
      IntPtr,
      Float,
      IntPtr,
      Double,
      IntPtr,
      Float,
      IntPtr,
      Double,
      IntPtr,
      Float,
      IntPtr,
      Double,
    );
typedef Int64PointerUnOp = Pointer<Int64> Function(Pointer<Int64>);
typedef QuadOp = int Function(int, int, int, int);
typedef DoubleUnaryOp = double Function(double);
typedef DecenaryOp =
    int Function(int, int, int, int, int, int, int, int, int, int);
typedef DoubleDecenaryOp =
    double Function(
      double,
      double,
      double,
      double,
      double,
      double,
      double,
      double,
      double,
      double,
    );
typedef VigesimalOp =
    double Function(
      int,
      double,
      int,
      double,
      int,
      double,
      int,
      double,
      int,
      double,
      int,
      double,
      int,
      double,
      int,
      double,
      int,
      double,
      int,
      double,
    );

main() {
  print('start main');

  DynamicLibrary ffiTestFunctions = dlopenPlatformSpecific(
    "ffi_test_functions",
  );

  {
    // A int32 bin op.
    BinaryOp sumPlus42 = ffiTestFunctions
        .lookupFunction<NativeBinaryOp, BinaryOp>("SumPlus42");

    var result = sumPlus42(3, 17);
    print(result);
    print(result.runtimeType);
  }

  {
    // As a leaf call.
    BinaryOp sumPlus42Leaf = ffiTestFunctions
        .lookupFunction<NativeBinaryOp, BinaryOp>("SumPlus42", isLeaf: true);

    final result = sumPlus42Leaf(3, 17);
    print(result);
    print(result.runtimeType);
  }

  {
    // Various size arguments.
    QuadOp intComputation = ffiTestFunctions
        .lookupFunction<NativeQuadOpSigned, QuadOp>("IntComputation");
    var result = intComputation(125, 250, 500, 1000);
    print(result);
    print(result.runtimeType);

    var mint = 0x7FFFFFFFFFFFFFFF; // 2 ^ 63 - 1
    result = intComputation(1, 1, 1, mint);
    print(result);
    print(result.runtimeType);
  }

  {
    // Unsigned int parameters.
    QuadOp uintComputation = ffiTestFunctions
        .lookupFunction<NativeQuadOpUnsigned, QuadOp>("UintComputation");
    var result = uintComputation(0xFF, 0xFFFF, 0xFFFFFFFF, -1);
    result = uintComputation(1, 1, 0, -1);
    print(result);
    print(result.runtimeType);
    print(-0xFF + 0xFFFF - 0xFFFFFFFF);
  }

  {
    // Architecture size argument.
    Pointer<NativeFunction<NativeFunc4>> p = ffiTestFunctions.lookup("Times3");
    UnaryOp f6 = p.asFunction();
    var result = f6(1337);
    print(result);
    print(result.runtimeType);
  }

  {
    // Function with double.
    DoubleUnaryOp times1_337Double = ffiTestFunctions
        .lookupFunction<NativeDoubleUnaryOp, DoubleUnaryOp>("Times1_337Double");
    var result = times1_337Double(2.0);
    print(result);
    print(result.runtimeType);
  }

  {
    // Function with float.
    DoubleUnaryOp times1_337Float = ffiTestFunctions
        .lookupFunction<NativeFloatUnaryOp, DoubleUnaryOp>("Times1_337Float");
    var result = times1_337Float(1000.0);
    print(result);
    print(result.runtimeType);
  }

  {
    // Function with many arguments: arguments get passed in registers and stack.
    DecenaryOp sumManyInts = ffiTestFunctions
        .lookupFunction<NativeDecenaryOp, DecenaryOp>("SumManyInts");
    var result = sumManyInts(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
    print(result);
    print(result.runtimeType);
  }

  {
    // Function with many arguments: arguments get passed in registers and stack.
    DecenaryOp sumManyInts = ffiTestFunctions
        .lookupFunction<NativeDecenaryOp2, DecenaryOp>("SumManySmallInts");
    var result = sumManyInts(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
    print(result);
    print(result.runtimeType);
  }

  {
    // Function with many double arguments.
    DoubleDecenaryOp sumManyDoubles = ffiTestFunctions
        .lookupFunction<NativeDoubleDecenaryOp, DoubleDecenaryOp>(
          "SumManyDoubles",
        );
    var result = sumManyDoubles(
      1.0,
      2.0,
      3.0,
      4.0,
      5.0,
      6.0,
      7.0,
      8.0,
      9.0,
      10.0,
    );
    print(result);
    print(result.runtimeType);
  }

  {
    // Function with many arguments, ints and doubles mixed.
    VigesimalOp sumManyNumbers = ffiTestFunctions
        .lookupFunction<NativeVigesimalOp, VigesimalOp>("SumManyNumbers");
    var result = sumManyNumbers(
      1,
      2.0,
      3,
      4.0,
      5,
      6.0,
      7,
      8.0,
      9,
      10.0,
      11,
      12.0,
      13,
      14.0,
      15,
      16.0,
      17,
      18.0,
      19,
      20.0,
    );
    print(result);
    print(result.runtimeType);
  }

  {
    // pass an array / pointer as argument
    Int64PointerUnOp assign1337Index1 = ffiTestFunctions
        .lookupFunction<Int64PointerUnOp, Int64PointerUnOp>("Assign1337Index1");
    Pointer<Int64> p2 = calloc(2);
    p2.value = 42;
    p2[1] = 1000;
    print((p2 + 1).address.toRadixString(16));
    print(p2[1]);
    Pointer<Int64> result = assign1337Index1(p2);
    print(p2[1]);
    print(assign1337Index1);
    print(assign1337Index1.runtimeType);
    print(result);
    print(result.runtimeType);
    print(result.address.toRadixString(16));
    print(result.value);
  }

  {
    // Passing in nullptr for a pointer argument results in a nullptr in c.
    Int64PointerUnOp nullableInt64ElemAt1 = ffiTestFunctions
        .lookupFunction<Int64PointerUnOp, Int64PointerUnOp>(
          "NullableInt64ElemAt1",
        );

    Pointer<Int64> result = nullableInt64ElemAt1(nullptr);
    print(result);
    print(result.runtimeType);

    Pointer<Int64> p2 = calloc(2);
    result = nullableInt64ElemAt1(p2);
    print(result);
    print(result.runtimeType);
    calloc.free(p2);
  }

  print("end main");
}